New Specification
for Cement
Extenders
M Mc Donald
10 November 2010
New Specification for Cement Extenders
Allow use of commonly
available materials
Why new
specifications
?
Modern statistical quality
control requirements
Align with international
standards
New Specification for Cement Extenders
Allow use of commonly
available materials
New
Corex
Chrome
Materials
slag
slag
???
New Specification for Cement Extenders
Modern statistical quality
control requirements
SANS 1491
SANS 1491
SANS 1491-1 to SANS 55167-1 & -2

Activity Index
ratio (in percent) of the
compressive strength of
mortar prisms made from
50% test cement and
50% ground granulated
blastfurnace slag,
relative to the 7 & 28 Day
compressive strength of
mortar prisms made from
100% test cement
SANS 1491
SANS 1491-2 to SANS 50450

Activity Index
ratio (in %) of the
compressive strength of
mortar bars, prepared
with 75 % test cement
plus 25 % fly ash by
mass, to mortar bars
prepared with 100 % test
cement.
The activity index at 28 &
90 Days shall not be less
than 75 % and 85 %,
respectively.
SANS 1491-2 to SANS 50450



Fineness
Category N:
The retained residue on
a 45um screen shall not
exceed 40 % by mass,
Category S:
The retained residue on
a 45um screen shall not
exceed 12 % by mass.
SANS 1491-2 to SANS 50450




Loss on ignition
Category A:
Not greater than 5,0 %
by mass
Category B:
Between 2,0 % and 7,0
% by mass
Category C:
Between 4,0 % and 9,0
% by mass
SANS 1491-2 to SANS 50450

Coal Co-combustion

Vegetable material like wood
chips, straw, olive shells and other
vegetable fibres






Green wood and cultivated
biomass
Animal meal
Municipal sewage sludge
Paper sludge
Petroleum coke
Virtually ash free liquid and
gaseous fuels
SANS 1491
SANS 1491-3 to SANS 53263

Activity Index
the ratio (in %) of the
compressive strength of
mortar bars, prepared
with 90 % test cement
and 10 % silica fume, to
the compressive strength
of mortar bars prepared
with 100 % test cement,
shall be at least 100 %
when tested at a mortar
age of 28 days.
SANS 1491-3 to SANS 53263

EN 934
The mortar containing
silica fume shall be mixed
with an amount of superplasticizer conforming to
EN 934-2 - so that the
mortar has a consistency
equivalent to the
reference mortar
SANS 1491
Part 4
Granulated Blastfurnace Slag
vitrified material made by rapid cooling
of a slag melt of suitable composition,
obtained by smelting iron ore in a
blastfurnace, consisting of at least
two thirds by mass of glassy slag and
possessing hydraulic properties when
suitably activated
Part 4
Corex
slag
Chrome
slag
New
Materials
???
Part 4
Include a new Part 4 for all
supplementary materials
not covered

Other metallurgical slag

Other combustion ash

Other ultra-fine super-pozzolans
SANS 1491







Registration of project proposal for evaluation
Project Approved
Circulation of Committee draft for comment
Decision to return to drafting phase
Circulation for formal approval (DSS for 60
days or 30 days for ISO adoption)
Close of approval period (after 30 days or 60
days)
Standard published